The present invention relates to a novel method and the corresponding device for the construction of a tunnel-like structure. More specifically, the invention relates to the construction of an underwater vehicle tunnel over the floor of a watercourse such as a river whereby assembly work on site is difficult.
The conventional method of under-river tunnel construction begins with excavation of earth or rock. If the earth or rock is structurally poor, supports must often be placed under the tunnel ceiling, or arch, as the tunnel is being driven. This excavation and ceiling work is the most costly and hazardous operation in the construction. As a general rule, a tunnel under a river is routed a substantial distance away from the riverbed which exaggerates further the total cost of such a structure. On top of this, the need for thorough geological survey, the possible need of driving a pilot tunnel at site, and the requirements of roof support and linings, etc. can all be very expensive operations for the construction of the vehicle tunnel.
I have found that these disadvantages of the conventional under-river tunnel construction can be eliminated by the employment of a flexible, double-layered fabric molding structure (hereinafter referred to as the "flexible mold") laying on and across the riverbed and by the introduction of both an inert fluid and a reactive and solidifiable fluid into the appropriate compartments or spacings of the flexible mold, respectively. Upon the consolidation of the reactive fluid the inert fluid may be withdrawn to provide the basic structure of the underwater tunnel. Hereinafter additional tiling and finishing work inside the tunnel will complete the construction work.
It is therefore one objective of this invention to provide a method for the construction of an underwater tunnel without underground excavation thereof.
It is another objective of this invention to provide a method of underwater construction without on-site assembly work for the basic structure of the instant tunnel.
It is an additional objective of the present invention to provide a method of underwater tunnel construction which conforms to the shape of a depression excavated onto the floor of the watercourse.
It is a further objective of this invention to provide a device which allows the underwater tunnel construction such as that described in the present invention.
These and other objectives of the invention, together with the advantages thereof, will become apparent from the following specifications and appended claims.